Dyeing and printing natural fiber with sulphur and vat dyestuffs



Patented July 28, 1931 UNITED STATES PATENT OFFICE CONRAD SCHOELLER, OF MANNHEIM, GERMANY, ASSIGNOR TO GENERAL ANILINE WORKS, INC., OF NEW YORK, N. Y., A CORPORATION OF DELAWARE I DYEING AND PRINTING NATURAL FIBER WITH SULPHUR AND VAT DYESTUFFS No Drawing. Application filed October 31, 1928, Serial No. 316,841, and in Germany December 13, 1926.

Hitherto, while it has been possible to dye wool and cotton themselves with dyestuffs of fairly good or very good fastness, for dyeing half wool it has only been possible to employ .1 substantive and acid dyestuffs of small fastness, frequently even by the employment of -would attack the wool and the like, by

- aliphatic, aroma-tic, or hydroaromatic amines or heterocyclic bases having an alkaline reactlon, which are not 1n ur1ous to animal fibers, in combination with hydrosulfite or other reducing agents, and also in cases where dyemg 1s carrled out at more elevated temperatures than those usually employed, for instance at temperatures near or at the boiling point of the vat, such-as for example with sulphur dyestufls, by adding'formaldehyde in order to maintain the excess hydrosulfite in an active condition during the dyeing process.

In accordance with the process of this invention deep uniform dyeings having .good properties of fastness are obtained, for example, with sulphur dyestufl's on half wool;

similarly with vatidyestuiis deep dyeings are obtained on wool Without injury to the fiber. The following, among others of the said amines and heterocyclic bases, have proved particularly suitable :triethanolamine, cy-

clohexyldiethanolamine, cyclohexylmonoethanolamine, pyridine.

The following examples will further illus-v trate how the invention may be carried into practical effect. but the invention is not restricted to these examples.

Ewumple 1 0.8 part of 100 per cent triethanolamine, 06 part of the sulphur dyestufi' free from alkali obtained by boiling 1.2. 1 dinitrophenol with sodium polysulfide (Colour Index 1924, No. 978), or 0.8 partof solid hydrosulfite and formaldehyde (which may be replaced by 0.3 part of a 30 per cent solution of formaldehyde are added to 100 parts of water and the whole warmed at 70 C. for 5 to 10 minutes. 100 parts of water and 3 parts of Glaubers salt (sodium sulfate) are then added and 10 parts of half wool serge introduced into the dye liquor. The whole is then heated at between 80 and 90 C. for an hour with good working; the serge is then squeezed out and allowed to hang for 15 minutes, rinsed and soaped for 10 minutes at 35 C. with a solution of 2 grams of soap per liter. A well covered, equal black dyeing, fast tov rubbing is obtained; the wool is not appreciably influenced, much less so than for example by said dyeing with chromium dyestu s.

The quantities of triethanolamind, Glaubers salt (sodium sulfate) hydrosulfite and formaldehyde-sodium-sulfoxylate) may be varied as also the temperature. Instead of formaldehyde other substances which combine with hydrosulfite, or glucose may be added.

Example 2 The process according to Example 1 is followed, the ingredients of the dye bath are as follows 100 parts of water, 2 parts of pyridine, 0.8 part "of the sulphur dyestufi described in Example 1, 0.5 part of solid hydrosulfite, 0.1 part of formaldehyde, 1 part of formaldehyde-sodium-sulfoxylate and then 4 parts of-Glaubers. salt and 100 parts of water. I I

Handsome black dyeings are obtained.

Ewample 3 4 parts of cyclohexylmonoethanolamlne (75 per cent), 0.6 part of solid hydrosulfite and 0.5 part of dimethoxydibenzanthrone are added to 200 parts of water at to 70 0., and after 10 minutes at this temperature 5 parts of wool yarn are introduced and dyed for 1 hour without movement. The yarn is then rinsed, oxidized, acidified with a solu: tion containing 1 cubic centimeter of sulfuric acid of 66 Baum per liter of water, rinsed 100 and soaped for one quarter of an hour at 45 C. with a solution of 4 grams of soap per liter.

A deep bright green dyeing is obtained, without injury to the wool.

Although the dyestuif may be quite well reduced by a much smaller quantity of amine, large quantities are preferable in order to prevent separatlon .of the dyestufi during dyeing.

Example 4 0.2 part'of cyclohexylmonoethanolamine per cent), 0.1 part of size glue, 0.2 part of solid hydrosulfite and 0.2 part of the dry leuco compound of the dyestuif obtainable by heating the condensation product of chloranil and aniline with ethyl alcohol, saturated with hydrogen sulphide, at a temperature of between 120 and 125 C. are added to 200 parts of water and warmed for 10 minutes at 50 0., 5 parts of w l yarn are then introduced into the dye liquor and dyed for an hour at 50C. without movement and finished as in Example 3.

The yarn is soaped for 10 minutes at 30 C. with a solution of 2 grams of soap per liter. Example 5 400 parts of water are warmed for 10 minutes at 50 C. with 0.4 part of cyclohexylmonoethanolamine, 0.2 part of size glue, 0.8 partof solid hydrosulfite and 0.2 part of the dyestufl' mentioned in Example 4; 5 parts of wool yarn are introduced and dyed for half an hour at this temperature without stirring; 1.5 parts of a 10 per cent ammonium sulfate solution 'are then added in small quantities and finally acetic acid until the bath is exhausted. The yarn is rinsed and soaped as in Example 4. Dyeings in no way inferior to those-obtained by the usual method with employment of ammonia are obtained, and moreover the material is not injured. Emample 6 W001 muslin is treated with chlorine in the manner customary for printing purposes, and printed with the following printmg mixture 50 grams of the sulphur dyestuif described in Example 1 grams of glycerine 70 grams of water 4 .200 grams of alkaline paste (see below) 400 grams ofBritish gum. 1 to 1.

grams of grape sugar (dextrose) 50 grams of formaldehyde-sodium-sulfoxylate l 50 grams of water 1000 grams heating to 70 C.

The alkaline paste is prepared by making 20 grams of wheat starch '50 grams of water 50 grams of dark burnt starch 150 grams of water into a paste, cooling the whole, then adding 10 grams of glycerine 400 grams of cyclohexyldiethanolamine, and stirring until cold. The printed material is dried, steamed for 3 minutes in a Mather-Flatt, well rinsed and soaped for 15 minutes at 35 C. with a solution of 2 grams of soap per liter. Deep shades fast to rubbing are obtained without damaging the wool. 1

What I claim is 1. In the dyeing andprinting of natural fibers as Well as mixed textures thereof with vat and sulphur dyestuffs the step which comprises solubilizing the said dyestufls, ins ead of by alkalies, by an organic base together with a reducing agent.

2. In the dyeing and printing of natural fibers as well as mixed textures thereof with vat and sulphur dyestuffs the step which comprises solubilizin the said dyestuffs, instead of by alkalies, y an organic base together with hydrosulfite. v

3. In the dyeing and printing of natural fibers as .well as mixed textures thereof with vat and sulphur dyestufi's the step which comprises solubilizing the said dyestuffs at higher temperatures than those usually applied fo'r dyeing, instead of by alkalies, by an organe base together with a reducing agent and formaldehyde.

In testimony whereof I have'hereunto set I 

